Add documentation for libstun and fix some docs elsewhere

1 files changed, 257 insertions, 18 deletions

diff --git a/stun/stunagent.h b/stun/stunagent.h
index 4f02f4d..d47b171 100644
--- a/stun/stunagent.h
+++ b/stun/stunagent.h
@@ -60,10 +60,28 @@
 
 #include <sys/types.h>
 
+/**
+ * StunAgent:
+ *
+ * An opaque structure representing the STUN agent.
+ */
 typedef struct stun_agent_t StunAgent;
 
 #include "stunmessage.h"
 
+/**
+ * StunCompatibility:
+ * @STUN_COMPATIBILITY_RFC3489: Use the STUN specifications compatible with
+ * RFC 3489
+ * @STUN_COMPATIBILITY_RFC5389: Use the STUN specifications compatible with
+ * RFC 5389
+ * @STUN_COMPATIBILITY_WLM2009: Use the STUN specifications compatible with
+ * Windows Live Messenger 2009 (a mix between RFC3489 and RFC5389, as well as
+ * a special usecase against a typo in their code)
+ * @STUN_COMPATIBILITY_LAST: Dummy last compatibility mode
+ *
+ * Enum that specifies the STUN compatibility mode of the #StunAgent
+ */
 typedef enum {
   STUN_COMPATIBILITY_RFC3489,
   STUN_COMPATIBILITY_RFC5389,
@@ -72,31 +90,40 @@ typedef enum {
 } StunCompatibility;
 
 
+/**
+ * StunValidationStatus:
+ * @STUN_VALIDATION_SUCCESS: The message is validated
+ * @STUN_VALIDATION_NOT_STUN: This is not a valid STUN message
+ * @STUN_VALIDATION_INCOMPLETE_STUN: The message seems to be valid but incomplete
+ * @STUN_VALIDATION_BAD_REQUEST: The message does not have the cookie or the
+ * fingerprint while the agent needs it with its usage
+ * @STUN_VALIDATION_UNAUTHORIZED_BAD_REQUEST: The message is valid but
+ * unauthorized with no username and message-integrity attributes.
+ * A BAD_REQUEST error must be generated
+ * @STUN_VALIDATION_UNAUTHORIZED: The message is valid but unauthorized as
+ * the username/password do not match.
+ * An UNAUTHORIZED error must be generated
+ * @STUN_VALIDATION_UNMATCHED_RESPONSE: The message is valid but this is a
+ * response/error that doesn't match a previously sent request
+ * @STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE: The message is valid but
+ * contains one or more unknown comprehension attributes.
+ * stun_agent_build_unknown_attributes_error() should be called
+ * @STUN_VALIDATION_UNKNOWN_ATTRIBUTE: The message is valid but contains one
+ * or more unknown comprehension attributes. This is a response, or error,
+ * or indication message and no error response should be sent
+ *
+ * This enum is used as the return value of stun_agent_validate() and represents
+ * the status result of the validation of a STUN message.
+ */
 typedef enum {
-  /* The message is validated */
   STUN_VALIDATION_SUCCESS,
-  /* This is not a valid STUN message */
   STUN_VALIDATION_NOT_STUN,
-  /* The message seems to be valid but incomplete */
   STUN_VALIDATION_INCOMPLETE_STUN,
-  /* The message does not have the cookie or the fingerprint
-   * while the agent needs it with its usage */
   STUN_VALIDATION_BAD_REQUEST,
-  /* The message is valid but unauthorized with no username and message-integrity
-     attributes. A BAD_REQUEST error must be generated */
   STUN_VALIDATION_UNAUTHORIZED_BAD_REQUEST,
-  /* The message is valid but unauthorized as the username/password do not match.
-     An UNAUTHORIZED error must be generated */
   STUN_VALIDATION_UNAUTHORIZED,
-  /* The message is valid but this is a response/error that doesn't match
-   * a previously sent request */
   STUN_VALIDATION_UNMATCHED_RESPONSE,
-  /* The message is valid but contains one or more unknown comprehension
-   * attributes. stun_agent_build_unknown_attributes_error should be called */
   STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE,
-  /* The message is valid but contains one or more unknown comprehension
-   * attributes. This is a response, or error, or indication message
-   * and no error response should be sent */
   STUN_VALIDATION_UNKNOWN_ATTRIBUTE,
 } StunValidationStatus;
 
@@ -157,39 +184,251 @@ struct stun_agent_t {
   StunAgentUsageFlags usage_flags;
 };
 
+/**
+ * StunDefaultValidaterData:
+ * @username: The username
+ * @username_len: The length of the @username
+ * @password: The password
+ * @password_len: The length of the @password
+ *
+ * This structure is used as an element of the user_data to the
+ * stun_agent_default_validater() function for authenticating a STUN
+ * message during validationg.
+ * <para> See also: stun_agent_default_validater() </para>
+ */
 typedef struct {
   uint8_t *username;
   size_t username_len;
   uint8_t *password;
   size_t password_len;
-} stun_validater_data;
+} StunDefaultValidaterData;
 
 
+/**
+ * StunMessageIntegrityValidate:
+ * @agent: The #StunAgent
+ * @message: The #StunMessage being validated
+ * @username: The username found in the @message
+ * @username_len: The length of @username
+ * @password: The password associated with that username. This argument is a
+ * pointer to a byte array that must be set by the validater function.
+ * @password_len: The length of @password which must also be set by the
+ * validater function.
+ * @user_data: Data to give the function
+ *
+ * This is the prototype for the @validater argument of the stun_agent_validate()
+ * function.
+ * <para> See also: stun_agent_validate() </para>
+ * Returns: %TRUE if the authentication was successful,
+ * %FALSE if the authentication failed
+ */
 typedef bool (*StunMessageIntegrityValidate) (StunAgent *agent,
     StunMessage *message, uint8_t *username, uint16_t username_len,
     uint8_t **password, size_t *password_len, void *user_data);
 
+/**
+ * stun_agent_default_validater:
+ * @agent: The #StunAgent
+ * @message: The #StunMessage being validated
+ * @username: The username found in the @message
+ * @username_len: The length of @username
+ * @password: The password associated with that username. This argument is a
+ * pointer to a byte array that must be set by the validater function.
+ * @password_len: The length of @password which must also be set by the
+ * validater function.
+ * @user_data: This must be an array of #StunDefaultValidaterData structures.
+ * The last element in the array must have a username set to NULL
+ *
+ * This is a helper function to be used with stun_agent_validate(). If no
+ * complicated processing of the username needs to be done, this function can
+ * be used with stun_agent_validate() to quickly and easily match the username
+ * of a STUN message with its password. Its @user_data argument must be an array
+ * of #StunDefaultValidaterData which will allow us to map a username to a
+ * password
+ * <para> See also: stun_agent_validate() </para>
+ * Returns: %TRUE if the authentication was successful,
+ * %FALSE if the authentication failed
+ */
 bool stun_agent_default_validater (StunAgent *agent,
     StunMessage *message, uint8_t *username, uint16_t username_len,
     uint8_t **password, size_t *password_len, void *user_data);
 
+/**
+ * stun_agent_init:
+ * @agent: The #StunAgent to initialize
+ * @known_attributes: An array of #uint16_t specifying which attributes should
+ * be known by the agent. Any STUN message received that contains a mandatory
+ * attribute that is not in this array will yield a
+ * #STUN_VALIDATION_UNKNOWN_REQUEST_ATTRIBUTE or a
+ * #STUN_VALIDATION_UNKNOWN_ATTRIBUTE error when calling stun_agent_validate()
+ * @compatibility: The #StunCompatibility to use for this agent. This will affect
+ * how the agent builds and validates the STUN messages
+ * @usage_flags: A bitflag using #StunAgentUsageFlags values to define which
+ * STUN usages the agent should use.
+ *
+ * This function must be called to initialize an agent before it is being used.
+ *
+ <note>
+   <para>
+    The @known_attributes data must exist in memory as long as the @agent is used
+    </para>
+    <para>
+    If the #STUN_AGENT_USAGE_SHORT_TERM_CREDENTIALS and
+    #STUN_AGENT_USAGE_LONG_TERM_CREDENTIALS usage flags are not set, then the
+    agent will default in using the short term credentials mechanism
+    </para>
+    <para>
+    The #STUN_AGENT_USAGE_USE_FINGERPRINT and #STUN_AGENT_USAGE_ADD_SOFTWARE
+    usage flags are only valid if the #STUN_COMPATIBILITY_RFC5389 or
+    #STUN_COMPATIBILITY_WLM2009 @compatibility is used
+    </para>
+ </note>
+ */
 void stun_agent_init (StunAgent *agent, const uint16_t *known_attributes,
-    StunCompatibility compatibility, uint32_t usage_flags);
+    StunCompatibility compatibility, StunAgentUsageFlags usage_flags);
+
+/**
+ * stun_agent_validate:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to build
+ * @buffer: The data buffer of the STUN message
+ * @buffer_len: The length of @buffer
+ * @validater: A #StunMessageIntegrityValidate function callback that will
+ * be called if the agent needs to validate a MESSAGE-INTEGRITY attribute. It
+ * will only be called if the agent finds a message that needs authentication
+ * and a USERNAME is present in the STUN message, but no password is known.
+ * The validater will not be called if the #STUN_AGENT_USAGE_IGNORE_CREDENTIALS
+ * usage flag is set on the agent, and it will always be called if the
+ * #STUN_AGENT_USAGE_FORCE_VALIDATER usage flag is set on the agent.
+ * @validater_data: A user data to give to the @validater callback when it gets
+ * called.
+ *
+ * This function is used to validate an inbound STUN message and transform its
+ * data buffer into a #StunMessage. It will take care of various validation
+ * algorithms to make sure that the STUN message is valid and correctly
+ * authenticated.
+ * <para> See also: stun_agent_default_validater() </para>
+ * Returns: A #StunValidationStatus
+ <note>
+   <para>
+   if the return value is different from #STUN_VALIDATION_NOT_STUN or
+   #STUN_VALIDATION_INCOMPLETE_STUN, then the @msg argument will contain a valid
+   STUN message that can be used.
+   This means that you can use the @msg variable as the @request argument to
+   functions like stun_agent_init_error() or
+   stun_agent_build_unknown_attributes_error().
+   If the return value is #STUN_VALIDATION_BAD_REQUEST,
+   #STUN_VALIDATION_UNAUTHORIZED or #STUN_VALIDATION_UNAUTHORIZED_BAD_REQUEST
+   then the @key in the #StunMessage will not be set, so that error responses
+   will not have a MESSAGE-INTEGRITY attribute.
+   </para>
+ </note>
+ */
 StunValidationStatus stun_agent_validate (StunAgent *agent, StunMessage *msg,
     const uint8_t *buffer, size_t buffer_len,
     StunMessageIntegrityValidate validater, void * validater_data);
+
+/**
+ * stun_agent_init_request:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to build
+ * @buffer: The buffer to use in the #StunMessage
+ * @buffer_len: The length of the buffer
+ * @m: The #StunMethod of the request
+ *
+ * Creates a new STUN message of class #STUN_REQUEST and with the method @m
+ * Returns: %TRUE if the message was initialized correctly, %FALSE otherwise
+ */
 bool stun_agent_init_request (StunAgent *agent, StunMessage *msg,
     uint8_t *buffer, size_t buffer_len, StunMethod m);
+
+/**
+ * stun_agent_init_indication:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to build
+ * @buffer: The buffer to use in the #StunMessage
+ * @buffer_len: The length of the buffer
+ * @m: The #StunMethod of the indication
+ *
+ * Creates a new STUN message of class #STUN_INDICATION and with the method @m
+ * Returns: %TRUE if the message was initialized correctly, %FALSE otherwise
+ */
 bool stun_agent_init_indication (StunAgent *agent, StunMessage *msg,
     uint8_t *buffer, size_t buffer_len, StunMethod m);
+
+/**
+ * stun_agent_init_response:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to build
+ * @buffer: The buffer to use in the #StunMessage
+ * @buffer_len: The length of the buffer
+ * @request: The #StunMessage of class #STUN_REQUEST that this response is for
+ *
+ * Creates a new STUN message of class #STUN_RESPONSE and with the same method
+ * and transaction ID as the message @request. This will also copy the pointer
+ * to the key that was used to authenticate the request, so you won't need to
+ * specify the key with stun_agent_finish_message()
+ * Returns: %TRUE if the message was initialized correctly, %FALSE otherwise
+ */
 bool stun_agent_init_response (StunAgent *agent, StunMessage *msg,
     uint8_t *buffer, size_t buffer_len, const StunMessage *request);
+
+/**
+ * stun_agent_init_error:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to build
+ * @buffer: The buffer to use in the #StunMessage
+ * @buffer_len: The length of the buffer
+ * @request: The #StunMessage of class #STUN_REQUEST that this error response
+ * is for
+ * @err: The #StunError to put in the ERROR-CODE attribute of the error response
+ *
+ * Creates a new STUN message of class #STUN_ERROR and with the same method
+ * and transaction ID as the message @request. This will also copy the pointer
+ * to the key that was used to authenticate the request (if authenticated),
+ * so you won't need to specify the key with stun_agent_finish_message().
+ * It will then add the ERROR-CODE attribute with code @err and the associated
+ * string.
+ * Returns: %TRUE if the message was initialized correctly, %FALSE otherwise
+ */
 bool stun_agent_init_error (StunAgent *agent, StunMessage *msg,
     uint8_t *buffer, size_t buffer_len, const StunMessage *request,
     StunError err);
+
+/**
+ * stun_agent_build_unknown_attributes_error:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to build
+ * @buffer: The buffer to use in the #StunMessage
+ * @buffer_len: The length of the buffer
+ * @request: The #StunMessage of class #STUN_REQUEST that this response is for
+ *
+ * Creates a new STUN message of class #STUN_ERROR and with the same method
+ * and transaction ID as the message @request.  It will then add the ERROR-CODE
+ * attribute with code #STUN_ERROR_UNKNOWN_ATTRIBUTE and add all the unknown
+ * mandatory attributes from the @request STUN message in the
+ * #STUN_ATTRIBUTE_UNKNOWN_ATTRIBUTES attribute, it will then finish the message
+ * by calling stun_agent_finish_message()
+ * Returns: The size of the message built
+ */
 size_t stun_agent_build_unknown_attributes_error (StunAgent *agent,
     StunMessage *msg, uint8_t *buffer, size_t buffer_len,
     const StunMessage *request);
+
+
+/**
+ * stun_agent_finish_message:
+ * @agent: The #StunAgent
+ * @msg: The #StunMessage to finish
+ * @key: The key to use for the MESSAGE-INTEGRITY attribute
+ * @key_len: The length of the @key
+ *
+ * This function will 'finish' a message and make it ready to be sent. It will
+ * add the MESSAGE-INTEGRITY and FINGERPRINT attributes if necessary. If the
+ * STUN message has a #STUN_REQUEST class, it will save the transaction id of
+ * the message in the agent for future matching of the response.
+ * Returns: The final size of the message built
+ */
 size_t stun_agent_finish_message (StunAgent *agent, StunMessage *msg,
    const uint8_t *key, size_t key_len);